Passive pressure regulation mechanism

ABSTRACT

A pump system including a drive mechanism that provides a pumping force, a primary pump including a first pump cavity, an actuating element in reciprocal relation with the first pump cavity, and an outlet fluidly connected to a reservoir, a force translator that facilitates pump force transfer from the drive mechanism to the actuating element, a pressure regulation mechanism including a reciprocating pump that includes a pump chamber including an inlet manifold fluidly connected to the reservoir, a valve located within the inlet manifold, and a reciprocating element in reciprocal relation with the pump chamber. The pressure regulation mechanism preferably passively ceases force transfer from the drive mechanism to the primary pump based on the pressure of the reservoir.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/797,846, filed 12 Mar. 2013, which claims the benefit of U.S.Provisional Application No. 61/613,406 filed 20 Mar. 2012, U.S.Provisional Application No. 61/637,206 filed 23 Apr. 2012, and U.S.Provisional Application No. 61/672,223 filed 16 Jul. 2012, which areincorporated in its entirety by this reference.

This application is also related to U.S. application Ser. No. 13/468,007filed 10 May 2012, which is incorporated in its entirety by thisreference.

TECHNICAL FIELD

This invention relates generally to the pumping field, and morespecifically to a new and useful passive pressure regulator in thepumping field.

BACKGROUND

Passive pressurization systems can be desirable in many applications,particularly in those wherein the extra weight of an electrical energystorage device or the additional complexity of digital controls can bedetrimental or inconvenient. However, passive pressurization systems cansuffer from over-pressurization of a reservoir, wherein thepressurization system continues to pump fluid into the reservoir evenafter the desired reservoir pressure is reached. Conventional systemstypically resolve this problem with a relief valve, wherein the reliefvalve vents the reservoir contents into the ambient environment when thereservoir pressure exceeds or meets the desired pressure. These systemslack a feedback loop that ceases continued pressurization of thereservoir when the desired pressure is reached, thereby reducing pumpcycles and increasing pump lifespan.

Thus, there is a need in the passive pressurization field to create anew and useful passive pressure regulation system.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic representation of the pressure regulationmechanism.

FIGS. 2A and 2B are schematic representations of the pressure regulationmechanism in the pressurized and depressurized modes.

FIGS. 3A and 3B are cutaway views of a variation of the pressureregulation mechanism placing the pump system in the pumping andnon-pumping modes, respectively.

FIGS. 4A and 4B are schematic representations of a second variation ofthe pressure regulation mechanism placing the pump system in the pumpingand non-pumping modes, respectively.

FIGS. 5A and 5B are schematic representations of a third variation ofthe pressure regulation mechanism placing the pump system in the pumpingand non-pumping modes, respectively.

FIGS. 6A and 6B are schematic representations of a fourth variation ofthe pressure regulation mechanism placing the pump system in the pumpingand non-pumping modes, respectively.

FIGS. 7A and 7B are schematic representations of a fifth variation ofthe pump system with the pressure regulation mechanism in thepressurized and depressurized modes, respectively.

FIG. 8 is a cutaway view of a variation of the valve.

FIGS. 9A and 9B are schematic representations of fluid flow through thepump system in the pumping and non-pumping modes, respectively.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiments of the inventionis not intended to limit the invention to these preferred embodiments,but rather to enable any person skilled in the art to make and use thisinvention.

As shown in FIG. 1, the passive pressure regulation mechanism 200 of thepump system 100 includes a pump body 220, an actuating mechanism 240,and a valve 260 having a threshold opening pressure. The valve 260 canadditionally include a threshold closing pressure. The pressureregulation mechanism 200 is preferably utilized in a pump system 100that includes a reservoir 20 and a primary pump 120 driven by a drivemechanism 300, wherein the primary pump 120 pressurizes the reservoir20. The passive pressure regulation mechanism 200 is preferably fluidlyconnected to a reservoir 20 by a fluid manifold and mechanicallyconnected to a primary pump 120, wherein the primary pump 120 receives apumping force from the drive mechanism 300 to pump fluid into thereservoir 20. The pressure regulation mechanism 200 preferably functionsto passively cease pressurization of the reservoir 20 when a thresholdreservoir pressure is reached. The pressure regulation mechanism 200preferably ceases pressurization by ceasing force application from thedrive mechanism 300 to the primary pump. Force application can be ceasedby disconnecting the primary pump from the drive mechanism 300, or byceasing force generation at the drive mechanism 300. This pressureregulation mechanism 200 can confer several benefits. First, thepressure regulation mechanism 200 passively controls the pressure of thereservoir 20, eliminating the need for sensors and other poweredcomponents. Second, the pressure regulation mechanism 200 canadditionally include a timing feature that controls the duration betweenpump system shut off and pump system restart.

The reservoir 20 fluidly coupled to the pressure regulation mechanism200 preferably receives fluid pumped by the pump system 100. Thereservoir 20 preferably has a substantially large volume relative to thepressure regulation mechanism 200, such that the pressure regulationmechanism 200 volume (i.e., the total volume defined by the actuatingmechanism 240 and the valve 260) is substantially insignificant relativeto the reservoir volume (i.e., fluid flow into passive pressureregulation mechanism 200 does not significantly change the reservoirpressure). The reservoir volume can additionally be substantially largerelative to the volume of the primary pump 120, such that the primarypump volume is substantially insignificant relative to the reservoirvolume. The reservoir 20 is preferably a tire interior, but canalternatively be a chamber, balloon, or any other suitable fluidreservoir 20. The reservoir 20 is preferably fluidly connected to thepressure regulation mechanism 200 at an outlet, and fluidly connected tothe primary pump 120 at an inlet.

The primary pump 120 of the pump system 100 functions to pump fluid intothe reservoir 20, thereby pressurizing the reservoir 20. The primarypump 120 preferably includes a pump cavity 122 and an actuating element124 that actuates within the pump cavity 122. The primary pump 120 ispreferably a positive displacement pump including a pump cavity 122 andactuating element 124 defining a lumen therebetween, wherein theactuating element 124 preferably forms a substantially fluid impermeableseal with and translates within the pump cavity 122 to create pressuredifferentials that move a fluid from the pump inlet to the pump outlet.However, the primary pump 120 can be any other suitable pump. Thepositive displacement pump is preferably a reciprocating pump whereinthe pump cavity 122 is a pump chamber and the actuating element 124 is areciprocating element, but can alternatively be a peristaltic pump,wherein the pump cavity 122 is a groove (e.g., circumferential groove)and the actuating element 124 is a diaphragm or tube. The reciprocatingelement can be a diaphragm, a piston, a diaphragm actuated by a piston(e.g., wherein the diaphragm defines the lumen and the piston receivesthe pumping force from the diaphragm to actuate the diaphragm, etc.), orany other suitable reciprocating element. The primary pump 120 ispreferably operable between a pumping mode and a non-pumping mode. Inthe pumping mode, the actuating element 124 receives a pumping forcefrom a drive mechanism 300 and translates along an actuation axisbetween a compressed position, wherein the actuating element 124 isproximal the closed end of the pump cavity 122, and a recoveredposition, wherein the actuating element 124 is distal the closed end. Inthe non-pumping mode, the actuating element 124 preferably does notreceive a pumping force from the drive mechanism 300, and fluid movementthrough the primary pump 120 is preferably ceased.

The pump system 100 preferably additionally includes a force translator400 that functions to connect the primary pump 120 to the drivemechanism 300. More preferably, the force translator 400 functions toconnect the actuating element 124 to the drive component 321 (e.g., cam320), wherein the force translator 400 translates relative motionbetween the drive mechanism 300 and the primary pump 120 into a variableoccluding force. The force translator 400 preferably applies a force ina radially outward direction from the rotational axis, but canalternatively apply a force in a radially inward direction, in adirection substantially parallel to the rotational axis, in a directionat an angle to the rotational axis, or in any other suitable direction.In a first alternative of the pump system 100, the force translator 400includes a planetary roller 401 that rolls about an interior or exteriorarcuate surface of the cam (e.g., as disclosed in U.S. application Ser.No. 13/187,848, filed 21 Jul. 2011, incorporated herein in its entiretyby this reference, but any other suitable system can be used). Thisalternative is preferably used when the primary pump 120 is aperistaltic pump, but can alternatively be used for any other suitablepump system 100. In a second alternative of the pump system 100, theforce translator 400 is a roller with a rotational axis that isstatically fixed to a point on the pump cavity 122, more preferably tothe actuation axis of the primary pump 120. This alternative ispreferably used with a reciprocating pump, but can alternatively be usedwith any other suitable pump. The roller is preferably in non-slipcontact with a bearing surface of the cam 320, wherein the cam 320preferably has a bearing surface with a varying curvature, such that theroller applies a variable force to the actuating element 124 as theroller rolls over the variable bearing surface. The roller slidesrelative to the actuating element 124, but can alternatively contact theactuating element 124 in any other suitable manner. In a thirdalternative of the pump system 100, the force translator 400 includes alinkage rotatably connected to a fixed point on the cam 320 androtatably coupled to the actuating element 124, wherein the linkagepreferably actuates the actuating element 124 through a compressionstroke and a recovery stroke as the fixed point nears and retreats fromthe pump cavity position, respectively. Alternatively, the linkage canactuate the actuating element 124 through the compression stroke andrecovery stroke as the fixed point retreats from and nears the pumpcavity 122, respectively. The linkage preferably includes a single link,but can alternatively include two or more links rotatably connected atthe respective ends. In a fourth alternative of the pump system 100, theforce translator 400 includes a keyed piece that joins with acomplimentary piece on drive mechanism 300 (e.g., tooth and gear).However, any other suitable force translator 400 can be used.

The drive mechanism 300 of the pump system 100 functions to provide apumping force to the primary pump 120. The pumping force is preferablyvariable, but can alternatively be constant. The drive mechanism 300 ispreferably passive and couples to a moving surface, but canalternatively be active (e.g., driven by a motor, etc.). The movingsurface is preferably a rotating surface (a surface configured torotate, such as a tire), but can alternatively be an oscillating surface(e.g., a wave), or any other suitable surface. The drive mechanism 300preferably generates the pumping force by facilitating relative motionbetween the drive mechanism 300 and the primary pump 120. In onevariation of the pump system 100, the primary pump 120 is staticallycoupled to a rotating surface while the drive mechanism 300 is heldsubstantially static relative to the frame in which the rotating surfaceis rotating. For example, the rotating surface can rotate relative to agravity vector, wherein the drive mechanism 300 is held substantiallystatic relative to the gravity vector. However, the pumping force can beotherwise generated. The drive mechanism 300 preferably includes a forcegenerator and a drive interface, wherein the force generator generatesthe pumping force, and the drive interface couples to the forcetranslator 400. However, the drive mechanism 300 can be otherwiseconfigured. The pump system 100 preferably includes one drive mechanism300 for each primary pump 120, but can alternatively include one drivemechanism 300 for multiple primary pumps, or have any other suitableconfiguration.

In one variation of the pump system 100, the drive mechanism 300includes a cam 320 and an eccentric mass 340. This drive mechanism 300is preferably configured to statically couple to a rotating surface, butcan alternatively be coupled to other surfaces. This drive mechanism 300preferably generates a pumping force (occluding force) in a radialdirection from a rotational axis of the drive mechanism 300, but canalternatively be a constant force, a force applied at any suitable angleto the rotational axis, or any other suitable force. The drive mechanism300 includes a rotational axis about which the drive mechanism 300rotates relative to the primary pump 120 (conversely, about which theprimary pump 120 rotates relative to the drive mechanism 300). Therotational axis of the drive mechanism 300 is preferably the rotationalaxis of the cam 320, but can alternatively be the rotational axis of theeccentric mass 340, the rotational axis about which the primary pumprotates, or any other suitable rotational axis. The pump system 100 ispreferably configured such that the rotational axis of the drivemechanism 300 is substantially aligned with the rotational axis of therotating surface when the pump system 100 is coupled to the rotatingsurface, but the pump system 100 can alternatively be configured suchthat the rotational axis of the drive mechanism 300 is offset from therotational axis of the rotating surface. The drive mechanism 300additionally includes a center of mass, determined from the mass andpositions of the cam 320 and the eccentric mass 340. The eccentric mass340 is preferably coupled to the cam 320 such that the center of mass ofthe drive mechanism 300 is offset from the rotational axis of the drivemechanism 300.

The cam 320 of the drive mechanism 300 functions to provide a surfaceagainst which the pumping force is generated. In a first variation, thecam 320 includes an arcuate bearing surface that interfaces with theprimary pump 120. More preferably, the arcuate bearing surfaceinterfaces with a roller force translator 400 of the primary pump 120.In one alternative, the cam 320 includes a bearing surface with avariable curvature that controls the magnitude of the substantiallylinear, radial force applied to the primary pump 120. The cam 320preferably functions to provide a substantially constant torque againstthe reciprocating element throughout the compression stroke, but canalternatively provide a variable torque against the reciprocatingelement throughout the compression or recovery strokes. The cam 320preferably includes a bearing surface, wherein the profile of thebearing surface preferably controls the magnitude of the forcethroughout the compression stroke. The bearing surface is preferablycontinuous, but can alternatively be discontinuous. The bearing surfaceis preferably defined on the exterior of the cam 320 (exterior bearingsurface or outer bearing surface) but can alternatively be definedwithin the interior of the cam 320 (interior bearing surface or innerbearing surface), wherein the bearing surface defines a lumen within thecam 320. The bearing surface is preferably arcuate, and preferably has anon-uniform curvature (e.g., a reniform profile). Alternatively, thebearing surface can have a uniform curvature (e.g., a circular profile),an angular profile, or any other suitable profile. The bearing surfacepreferably includes a compression portion and a recovery portion,corresponding to the compression stroke and the recovery stroke of theprimary pump 120, respectively. The compression portion is preferablycontinuous with the recovery section, but can alternatively bediscontinuous. The bearing surface preferably has a first section havinga high curvature (preferably positive curvature or convex butalternatively negative curvature or concave) adjacent a second sectionhaving low curvature (e.g., substantially flat or having negativecurvature compared to the first section). The bearing surface preferablyadditionally includes a third section connecting the first and secondsections, wherein the third section preferably provides a substantiallysmooth transition between the first and second sections by having a lowcurvature adjacent the first section and a high curvature adjacent thesecond section. The compression portion preferably begins at the end ofthe second section distal the first section, extends along the thirdsection, and ends at the apex of the first section. The compressionportion is preferably convex (e.g., when the bearing surface is anexternal bearing surface), but can alternatively be concave. The apex ofthe first section preferably corresponds to the top of the compressionstroke (compressed position). The recovery portion preferably begins atthe apex of the first section, extends along the second section, andends at the end of the second section distal the first section. Therecovery portion is preferably substantially flat or concave (e.g., whenthe bearing surface is an external bearing surface), but canalternatively be convex. The end of the second section preferablycorresponds to the bottom of the recovery stroke (recovered position).The slope of the compression portion is preferably less than 30 degrees,but can alternatively have any suitable angle. When a roller is used asthe force translator 400, the curvature of the bearing surface ispreferably at least three times larger than the roller curvature orroller diameter, but can alternatively be larger or smaller. However,the bearing surface can have any suitable profile. The cam 320 ispreferably substantially planar with the bearing surface defined alongthe side of the cam 320, in a plane normal to the rotational axis of thecam (e.g., normal the broad face of the cam). The bearing surface ispreferably defined along the entirety of the cam side, but canalternatively be defined along a portion of the cam side. The generatedpump force is preferably directed radially outward of the rotationalaxis, more preferably along a plane normal to the rotational axis.Alternatively, the cam 320 can have a rounded or otherwise profiled edgesegment (transition between the cam broad face and the cam side),wherein the bearing surface can include the profiled edge.Alternatively, the arcuate surface is defined by a face of the camparallel to the rotational axis of the cam 320, wherein the generatedpump force can be directed at any suitable angle relative to therotational axis, varying from parallel to the rotational axis to normalto the rotational axis. The compression portion preferably encompassesthe majority of the cam profile, but can alternatively encompass halfthe cam profile or a small portion of the cam profile. In one variation,the compression portion covers 315 degrees of the cam profile, while therecovery portion covers 45 degrees of the cam profile. However, thecompression and recovery portions can cover any other suitableproportion of the cam profile.

In another alternative, the cam 320 is a disk with a substantiallycircular profile. In yet another alternative, the cam 320 is a spheresegment or catenoid, wherein the bearing surface is preferably definedalong the arcuate surface. In yet another alternative, the cam 320 is abearing rotatably coupled about an axle statically coupled to therotating surface. The cam 320 can alternatively have any other suitableform factor or configuration.

The eccentric mass 340 (hanging mass) of the drive mechanism 300functions to offset the center of mass of the drive mechanism 300 fromthe rotational axis of the drive mechanism 300. This offset can functionto substantially retain the angular position of the cam 320 relative toa gravity vector, thereby engendering relative motion between the drivemechanism 300 and the primary pump 120 statically coupled to therotating surface (that rotates relative to the gravity vector). Theeccentric mass 340 is preferably a substantially homogenous piece, butcan alternatively be heterogeneous. The eccentric mass 340 is preferablya distributed mass (e.g., extends along a substantial portion of an arccentered about the rotational axis), but can alternatively be a pointmass. The eccentric mass 340 is preferably curved, but can alternativelybe substantially flat, angled, or have other suitable shapes. The radiusof the eccentric mass curvature is preferably maximized, such that theeccentric mass 340 traces an arcuate section of the energy extractionsystem perimeter. However, the eccentric mass 340 can have any othersuitable curvature. The eccentric mass 340 preferably extends at least80 degrees about the rotational axis of the drive mechanism 300, morepreferably 180 degrees about the rotational axis, but can extend more orless than 180 degrees about the rotational axis. The eccentric mass 340preferably has substantially more mass than the cam 320, but canalternatively have a substantially similar mass or a smaller mass. Theeccentric mass 340 preferably imparts 2 in-lb (0.225 Nm) of torque onthe cam 320, but can alternatively impart more or less torque.

The eccentric mass 340 is preferably a separate piece from the cam 320,and is preferably coupled to the cam 320 by a mass couple 360. Theeccentric mass 340 can be statically coupled to the cam 320 or rotatablycoupled to the cam 320. In the variation wherein the eccentric mass 340is statically coupled to the cam 320, the eccentric mass 340 can becoupled to the cam 320 at the rotational axis of the cam 320, at therotational axis of the drive mechanism 300, offset from the rotationalaxis of the cam 320, or at any other suitable portion of the cam 320.The eccentric mass 340 can be permanently connected to the cam 320.Alternatively, the eccentric mass 340 can be transiently connected(removably coupled) to the cam 320, wherein the eccentric mass 340 canbe operable between a coupled mode wherein the eccentric mass 340 iscoupled to the cam 320 and a decoupled mode wherein the eccentric mass340 is rotatably coupled to the cam 320 or otherwise decoupled fromangular cam motion. The mass couple 360 preferably has a high moment ofinertia, but can alternatively have a low moment of inertia. The masscouple 360 is preferably a disk, but can alternatively be a lever arm,plate, or any other suitable connection. The mass couple 360 preferablycouples to the broad face of the cam 320, but can alternatively coupleto the edge of the cam 320, along the exterior bearing surface of thecam 320, to the interior bearing surface of the cam 320, to an axleextending from of the cam 320 (wherein the cam 320 can be staticallyfixed to or rotatably mounted to the axle), or to any other suitableportion of the cam 320. The mass couple 360 can couple to the cam 320 byfriction, by a transient coupling mechanism (e.g., complimentaryelectric or permanent magnets located on the cam 320 and mass couple360, a piston, a pin and groove mechanism, etc.), by bearings, or by anyother suitable coupling means.

In another variation of the pump system 100, the drive mechanism 300 canbe a linear actuator, such as a mechanical actuator, hydraulic actuator,pneumatic actuator, piezoelectric actuator, electro-mechanical actuator,or any other suitable linear actuator. The actuating portion of thelinear actuator preferably connects to the actuating element 124 of theprimary pump 120, but can alternatively connect with the pump cavity 122of the primary pump 120. The linear actuator is preferably passive, butcan alternatively be driven by a motor (e.g., an electric motor).

In another variation of the pump system 100, the drive mechanism 300 canbe rotary actuator, such as a torque motor, electric motor, servo,stepper motor or any other suitable rotary actuator. The actuatingportion of the rotary actuator preferably connects to the actuatingelement 124 of the primary pump 120 through the force translator 400that converts the rotational motion into a linear motion, but canalternatively connect with the pump cavity 122 of the primary pump 120through the force translator 400.

The pressure regulation mechanism 200 of the pump system 100 functionsto cease pumping of the primary pump 120 when the reservoir pressureexceeds a threshold pressure. The pressure regulation mechanism 200includes a pump body 220, an actuating mechanism 240, and a valve 260,wherein the valve 260 is fluidly connected to the pump body inlet andthe actuating mechanism 240 actuates relative to a closed end of thepump body 220. The pump body 220 and actuating mechanism 240 preferablyform a piston pump, wherein the pump body 220 is a pump chamber and theactuating mechanism 240 is a reciprocating element. The pump body 220and actuating mechanism 240 can alternatively form any other suitablereciprocating pump or positive displacement pump. As shown in FIGS. 2Aand 2B, the pressure regulation mechanism 200 is preferably operable ina pressurized mode and a depressurized mode. The pressurized mode ispreferably achieved when the reservoir pressure exceeds the thresholdpressure. More preferably, the pressurized mode is achieved when thereservoir pressure exceeds the opening pressure of the valve 260. In thepressurized mode, the valve 260 is preferably in an open position andpermits fluid flow from the reservoir 20 into the pump body 220, whereinthe pressure of the ingressed fluid places the actuating mechanism 240in a pressurized position. In the pressurized position, the actuatingmechanism 240 preferably ceases pumping force application to the primarypump 120. In the depressurized mode, the valve 260 is preferably in aclosed position and prevents fluid flow from the reservoir 20 into thepump body 220, wherein a return mechanism places the actuating mechanism240 in a depressurized position. The pump system 100 preferably includesat least one pressure regulation mechanism 200, but can alternativelyinclude any suitable number of pressure regulation mechanisms.

The position of the pressure regulation mechanism 200, more preferablythe position of the pump body 220, is preferably statically connected tothe primary pump position, but can alternatively be moveably connectedto the primary pump position. The angular position of the pressureregulation mechanism 200 is preferably maintained relative to theprimary pump position, but the radial or linear distance canalternatively be maintained. The actuation axis of the pressureregulation mechanism 200 is preferably in the same plane as theactuation axis of the primary pump 120, but can alternatively be indifferent planes, perpendicular to the actuation axis of the primarypump 120, or arranged in any other suitable manner. The pressureregulation mechanism 200 is preferably arranged relative to the primarypump 120 such that the direction of the compression stroke of thepressure regulation mechanism 200 differs from the direction of thecompression stroke of the primary pump 120. The direction of thecompression stroke of the pressure regulation mechanism 200 directlyopposes the direction of the compression stroke of the primary pump 120(e.g., the closed end of the pump cavity 122 is distal the closed end ofthe pump body 220, and the actuating element 124 is proximal thereciprocating element, wherein the actuation axes are aligned or inparallel), but can alternatively be at an angle to the direction of thecompression stroke of the primary pump 120. Alternatively, the pressureregulation mechanism 200 can be arranged such that the compressionstroke of the pressure regulation mechanism 200 and the compressionstroke of the primary pump 120 have substantially the same direction(e.g., the actuation axes are aligned or in parallel).

The pump body 220 functions to cooperatively define a pressurizablelumen with the actuating mechanism 240. The pump body 220 is preferablysubstantially rigid, but can alternatively be flexible. The pump body220 is preferably an open pump body 220 with a closed end, wherein thepump body 220 preferably includes a closed end (bottom), walls extendingfrom the closed end, and an opening opposing the closed end. However,the pump body 220 can alternatively have two open ends or any othersuitable configuration. The closed end is preferably substantially flat,but can alternatively be curved or have any other suitable geometry. Thewalls are preferably substantially flat, but can alternatively be curvedor have any other suitable geometry. The walls preferably join with theclosed end at an angle, more preferably at a right angle, but thetransition between the walls and the closed end can alternatively besubstantially smooth (e.g., have a bell-shaped or paraboloidlongitudinal cross section). The closed end is preferably substantiallyparallel to the opening defined by the walls, but can alternatively beoriented at an angle relative to the opening. The pump body 220 can be agroove defined in an arcuate or prismatic piece (e.g., in a longitudinalor lateral direction), a cylinder, a prism, or any other suitable shape.The pump body 220 preferably has a substantially symmetrical lateralcross section (e.g., circular, ovular, or rectangular cross section,etc.), but can alternatively have an asymmetrical cross section. Thepump body 220 is preferably oriented within the pump system 100 suchthat the closed end is substantially normal to a radial vector extendingfrom the rotational axis of the drive mechanism 300 (e.g., the normalvector from the closed end is substantially parallel to the radialvector), but can alternatively be oriented with the closed end at anangle to the radial vector. The pump body 220 is preferably orientedwith the opening proximal and the closed end distal the rotational axis,particularly when the pump body 220 rotates about the cam exterior, butcan alternatively be oriented with the opening distal and the closed endproximal the rotational axis, particularly when the pump body 220rotates about the cam interior, or oriented in any other suitableposition relative to the rotational axis.

The actuating mechanism 240 functions to control the pumping mode of theprimary pump 120 based on the pressure within the pump body 220. Theactuating mechanism 240 preferably translates within the pump body 220.The actuating mechanism 240 preferably forms a fluid seal with the pumpbody 220 to define a lumen, but can alternatively be located within thelumen of the pump body 220. The actuating mechanism 240 preferablytranslates along an actuation axis substantially aligned with thelongitudinal axis of the pump body 220, but can alternatively actuatealong any other suitable axis. The actuating mechanism 240 is preferablya piston coupled to a diaphragm, but can alternatively be asubstantially flat surface, a piston, a roller, a cup, by substantiallysimilar to the force translator 400, or have any other suitable formfactor. The diaphragm is preferably a domed diaphragm with a foldedperimeter, but can alternatively be any other suitable diaphragm.

The actuating mechanism 240 is preferably operable between a pressurizedposition and a depressurized position, corresponding to the pressurizedmode and depressurized mode, respectively. The pressurized position ispreferably achieved when the pump body lumen is pressurized to thethreshold or reservoir pressure (wherein the actuating mechanismfunctions as a force element 241), and the depressurized position ispreferably achieved when the pump body lumen is at a pressure less thanthe threshold pressure. The actuating mechanism 240 is preferablylocated at a position distal the closed end of the pump body 220 in thepressurized position, and is preferably located at a position proximalthe closed end of the pump body 220 in the depressurized position. Theactuating mechanism 240 can be beyond the pump body 220, level with thepump body opening, or encompassed by the pump body 220 when in thepressurized position. The actuating mechanism 240 is preferably levelwith the pump body opening or encompassed by the pump body 220(retracted within the lumen) when in the depressurized position, but canalternatively be beyond (external) the pump body 220 when in thedepressurized position. The actuating mechanism 240 can additionallyinclude a return element (e.g., a spring, the primary pump 120, anotherpressurizable compartment, etc.) that applies a return force to returnthe actuating mechanism 240 to the depressurized position.

The depressurized position can include a compressed position and arecovered position. In the compressed position, a portion of theactuating mechanism 240 (e.g., the center) is preferably proximal thepump body closed end. In the recovered position, the portion of theactuating mechanism 240 is preferably distal the pump body closed end,and is preferably proximal the pump body opening. The actuatingmechanism 240 preferably travels along a compression stroke totransition from the recovered position to the compressed position, andtravels along a recovery stroke to transition from the compressedposition to the recovered position.

In a first variation of the pressure regulation mechanism 200, theactuation mechanism decouples the primary pump 120 or a primary pumpcomponent from drive mechanism 300 when in the pressurized position, andpermits primary pump coupling with the drive mechanism 300 when in thedepressurized position. An example of this variation in thedepressurized and pressurized positions is shown in FIGS. 3A and 3B,respectively. The actuating mechanism 240 preferably decouples the forcetranslator 400 from the drive mechanism 300, but alternatively decouplesthe actuating element 124 or the entirety of the primary pump 120 fromthe drive mechanism 300. The actuating mechanism 240 preferably movesthe primary pump component along the actuation axis of the primary pump120, away from the cam 320, when transitioning from the depressurizedposition to the pressurized position. However, the actuating mechanism240 can move the primary pump component at an angle to the actuationaxis of the primary pump 120, away from the cam 320 (e.g., in aperpendicular direction). The actuating mechanism 240 preferablytranslates the primary pump component within the plane encompassing theactuation axis or the pump body 220, but can alternatively translate theprimary pump component out of said plane. The force exerted on theactuating mechanism 240 by the return element of the pump regulationsystem preferably couples the primary pump component with the drivemechanism 300 while returning the actuating mechanism 240 to thedepressurized position, but the pump system 100 can alternativelyinclude a second return element that couples the primary pump componentto the drive mechanism 300 (e.g., a spring biased opposing the directionthat the actuating mechanism 240 moves the primary pump component,etc.). The second return element preferably returns the primary pumpcomponent contact with the drive mechanism 300 when the decoupling forceof the actuating mechanism 240 falls below the return force provided bythe second return element.

A portion of the actuating mechanism 240 is preferably staticallycoupled to a portion of the primary pump 120, wherein actuatingmechanism actuation results in a positional change of the primary pump120 or a primary pump component. More preferably, actuating mechanismactuation preferably selectively couples and decouples the primary pump120 from the drive mechanism 300 when the actuating mechanism 240 is inthe depressurized and pressurized positions, respectively. The actuatingmechanism 240 is statically coupled to the force translator 400, but canalternatively be statically coupled to the actuating element 124,statically coupled to the primary pump 120 as a whole, or staticallycoupled to any other suitable primary pump component. The actuatingmechanism 240 is preferably statically coupled to the primary pumpcomponent by a frame 242, but can alternatively be coupled by a housingencapsulating the pump system 100, or by any other suitable couplingmechanism. The frame 242 can be aligned within the plane encompassingthe actuation axis of the primary pump 120, within the planeencompassing the actuation axis of the pressure regulation mechanism200, extend out of either of said two planes, or be otherwise orientedrelative to the pump system 100. In a specific example, the forcetranslator 400 is a roller, wherein the actuating mechanism 240 iscoupled to the rotational axis of the roller by a frame 242 aligned witha plane encompassing both the actuation axis of the pressure regulationmechanism 200 and the actuation axis of the primary pump 120 (whereinthe pressure regulation mechanism 200 and primary pump 120 preferablyshare a common plane). Alternatively, the actuating mechanism 240transiently couples to the primary pump component when in thepressurized position, and is retracted away from the primary pumpcomponent when in the depressurized position.

In a second variation of the pressure regulation mechanism 200, theactuating mechanism 240 decouples the force translator 400 from theprimary pump 120 in the pressurized position, and permits forcetranslator coupling with the primary pump 120 when in the depressurizedposition. An example of this variation in the depressurized andpressurized positions is shown in FIGS. 4A and 4B, respectively.

The actuating mechanism 240 preferably connects to and moves the forcetranslator linear position relative to the drive mechanism 300 when inthe pressurized position, but can alternatively connect to and move theprimary pump 120 relative to the force translator 400 and drivemechanism 300. The actuating mechanism 240 preferably moves the forcetranslator 400 out of the common plane shared by the primary pump 120and the drive mechanism 300, but can alternatively move the forcetranslator 400 out of line with the actuation axis (e.g., perpendicular,within the common plane). The actuating mechanism 240 can be staticallycoupled to the force translator 400 or primary pump 120 by a frame 242,a weld, or any other suitable coupling mechanism. Alternatively, theactuating mechanism 240 can be transiently coupled to the forcetranslator 400 or primary pump 120, wherein the actuating mechanism 240can be a piston or rod that transiently couples to the force translator400 or primary pump 120 through a coupling feature (e.g., a groove) orfriction, (e.g., as a friction element 243).

In a third variation of the pressure regulation mechanism 200, theactuating mechanism 240 ceases force generation. In one alternative, thepressure regulation mechanism 200 statically couples the drive mechanism300 to the primary pump 120, ceasing force generation by eliminating therelative motion between the drive mechanism 300 and the primary pump120. Examples of this variation in the depressurized position are shownin FIGS. 5A and 6A, respectively, and pressurized positions are shown inFIGS. 5B and 6B, respectively. For example, when the drive mechanism 300includes a cam 320 and eccentric mass 340, the actuating mechanism 240can statically couple the angular position of the cam 320 with theangular position of the primary pump 120 in the pressurized position,and decouple the angular position of the cam 320 from the angularposition of the primary pump 120 in the depressurized position. In aspecific example, the actuating mechanism 240 is a rod that couples tothe cam broad face by friction. In another specific example, theactuating mechanism 240 is a rod that extends into a groove in the camface when in the pressurized position and is retracted from the groovewhen in the depressurized position. In another specific example, theactuating mechanism 240 statically couples to the arcuate bearingsurface of the cam 320. However, other mechanisms of transientlyretaining the cam angular position can be envisioned. In anotherexample, the actuating mechanism 240 can statically couple the angularposition of the eccentric mass 340 with the angular position of theprimary pump 120. In a specific example, the actuating mechanism 240 caninclude a rod that couples to the broad face of the eccentric mass 340or to the mass couple 360 by friction. In another specific example, theactuating mechanism 240 is a rod that extends into a groove in theeccentric mass face when in the pressurized position and is retractedfrom the groove when in the depressurized position. However, othermechanisms of transiently retaining the eccentric mass angular positioncan be envisioned. In another example, the pump cavity 122 of theprimary pump 120 can be statically coupled to the drive mechanism 300,such that relative motion between the actuating element 124 and the pumpcavity 122 is ceased (e.g., when a linear or rotary actuator is used).In another alternative, the pressure regulation mechanism 200 decouplesthe force generator from the drive interface of the drive mechanism 300.For example, when the cam 320 and eccentric mass 340 are transientlycoupled by a transient coupling mechanism, the actuating mechanism 240can actuate the cam 320, eccentric mass 340, or coupling mechanism todecouple the cam 320 from the eccentric mass 340. In one specificexample, if the cam 320 is coupled to the eccentric mass 340 along therespective broad faces by a ring of magnets 362 encircling therotational axis, as shown in FIG. 7A, the actuating mechanism 240 canextend through a hole in the cam 320 (or eccentric mass 340) and pushagainst the broad face of the eccentric mass 340 (or cam 320) todecouple the eccentric mass 340 from the cam 320, as shown in FIG. 7B.The actuating mechanism 240 can be statically coupled to the forcetranslator 400 or primary pump 120 by a frame 242 or other couplingmechanism. Alternatively, the actuating mechanism 240 can be transientlycoupled to the force translator 400 or primary pump 120, wherein theactuating mechanism 240 can be a piston or rod that couples to the forcetranslator 400 or primary pump 120.

In another variation of the pressure regulation mechanism, the pressureregulation mechanism 200 switches the primary pump 120 from the pumpingmode and a locked mode. The primary pump 120 preferably pumps fluid inthe pumping mode and does not pump fluid in the locked mode. Morepreferably, components of the pump system are held in static relationrelative to each other in the locked mode, such that the actuatingelement 124 is held substantially static. The primary pump 120 ispreferably placed in the locked mode when the pressure of the reservoir20 exceeds the opening threshold pressure of the valve 260, and ispreferably placed in the pumping mode when the pressure of the reservoir20 falls below the closing threshold pressure of the valve 260. Morespecifically, when the pressure of the reservoir 20 exceeds the openingthreshold pressure, the valve 260 opens, allowing pressurized air toflow from the reservoir 20 into the compression volume of the primarypump 120, substantially retaining the actuating element 124 in theinitial position of the compression stroke (e.g., in the recoveredposition). In this manner, the increased force of pressurized air on theactuating element 124 substantially opposes cam motion when theactuating element 124 is located at the second section of the camprofile, but can alternatively or additionally oppose cam motion whenthe actuating element 124 is located at the first section or thirdsection of the cam profile. Since the cam 320 is preferably configuredto only apply a small force to the actuating element 124 at the secondsection, the cam 320 cannot overcome the large back force applied by thebackflow on the actuating element 124. These aspects of the pump systemeffectively cease pumping within the primary pump 120. The force appliedby the backflow prevents cam movement relative to the primary pump 120,causing the cam 320 and subsequently, the eccentric mass 340, to rotatewith the pump system 10. When the pump system includes multiple pumps,all the pumps are preferably flooded with pressurized air.Alternatively, a single pump can be flooded with pressurized air,alternating pumps can be flooded with pressurized air, or any othersuitable subset of the pumps can be flooded to cease pumping.

However, any other suitable means of ceasing pumping force applicationto the actuating element can be used.

The valve 260 of the pressure regulation mechanism 200 functions toselectively permit fluid flow into the pump body 220 of the pressureregulation system. The valve 260 preferably has an opening thresholdpressure substantially equal to the desired reservoir pressure (e.g.,the upper limit of a desired reservoir pressure range), and canadditionally have a closing threshold pressure under, over, or equal tothe desired reservoir pressure (e.g., the lower limit of a desiredreservoir pressure range). The valve 260 can additionally function as atimer, and have a pumping resumption pressure at which primary pumppumping is resumed. The pumping resumption pressure is preferablydetermined by the ratio of the first and second pressurization areaswithin the valve. Alternatively, the pressure regulation mechanism 800can include a timer that functions to delay the resumption of pumpingafter the closing threshold pressure is reached. The valve 260 ispreferably located in the fluid manifold fluidly connecting thereservoir 20 with the pump body 220 (e.g., be valve 21 when thereservoir 20 is the tire interior, as shown in FIGS. 9A and 9B).However, the valve 260 can be located within the reservoir 20 or withinthe pump body inlet. The opening threshold pressure is preferably ahigher pressure than the closing threshold pressure, wherein the openingand closing threshold pressures are preferably determined by the returnforce applied by the return element. The valve state is preferablydetermined by the pressure within the second reservoir 500. The pumpingresumption pressure is preferably lower than the closing thresholdpressure, but can alternatively be higher than the closing thresholdpressure or be any suitable pressure. The valve 260 is preferablyoperable between an open mode when a reservoir pressure exceeds anopening threshold pressure, wherein the valve 260 permits fluid flowfrom the reservoir 20 into the pump body 220, and a closed mode when thereservoir pressure is below the closing threshold pressure, wherein thevalve 260 prevents fluid flow from the reservoir 20 into the pump body220. Pumping by the primary pump 200 is preferably resumed when thepressure within the second pump 820 falls below the pumping resumptionpressure, but can alternatively be resumed when the reservoir pressurefalls below the closing threshold. The valve 260 is preferably asnap-action valve, but can alternatively be any other suitable valve.The valve 260 preferably includes a valve member 261 that seats within avalve body 262, and can additionally include a return mechanism 263(e.g., a spring) that biases the valve member 261 against the valve body262. The valve member 261 and valve body 262 can be different materials(e.g., to compensate for material expansion due to temperature changes),or can be made of the same material or materials with similar expansioncoefficients.

In one variation of the pressure regulation mechanism 200, thesnap-action valve is substantially similar to the valve described inU.S. application Ser. No. 13/468,007 filed 10 May 2012.

In another variation of the pressure regulation mechanism 200, as shownin FIG. 8, the snap-action valve includes a valve member 261, a valvebody 262, a spring, a first volume 264, a second volume 265, a reservoirchannel 266, and a manifold channel 267. The spring, or return element263, biases the valve body 262 against the valve member 261. The springconstant of the spring is preferably selected based on the desiredreservoir pressure (threshold pressure or cracking pressure) and thedesired valve operating characteristics. The first volume 264 ispreferably defined between the valve body 262 and valve member 261, andpreferably has a first pressurization area normal to a direction ofspring force application. The second volume 265 is preferably alsodefined between the valve body 262 and valve member 261, and preferablyhas a second pressurization area normal to the direction of spring forceapplication. The reservoir channel 266 preferably fluidly connects thefirst volume 264 with the reservoir 20. The manifold channel 267 ispreferably defined through the valve body 262, and is preferably fluidlyconnected to the pressure regulation mechanism 200. The manifold channel267 is preferably defined along the axis of return force application,opposing the return element across the valve member 261, but canalternatively be defined in any other suitable location. The valve 260can additionally include a timing mechanism fluidly coupling the secondvolume 265 to an ambient environment, wherein the timing mechanismpreferably leaks air at a substantially controlled rate. In onevariation, the timing mechanism is a timing channel that has a crosssection selected based on a desired leak rate. The ratio of the firstpressurization area to the second pressurization area is preferablyselected based on the desired amount of time the valve 260 takes torecover the closed position, but can alternatively be any suitableratio. However, the timing mechanism can be a porous plug (e.g., whereinthe porosity can be selected based on the desired leak rate), an airpermeable membrane, or any other suitable gas permeable mechanism thatleaks air at a controlled rate. The combined volume of the first andsecond volumes are preferably substantially insignificant relative tothe reservoir volume. The valve 260 is preferably operable between anopen position and closed position. In the open position, the valve body262 and valve member 261 cooperatively define a connection channelfluidly connecting the first volume 264 with the second volume 265,wherein the valve member 261 is located distal the valve body 262. Theopen position is preferably achieved when a pressure force generated bya pressure within the first volume 264 overcomes the spring forceapplied by the spring on the valve body 262. In the closed mode, thevalve member 261 and valve body 262 cooperatively seal the connectionchannel and the valve member 261 substantially seals the manifoldchannel 267, wherein the valve member 261 seats against the valve body262. The closed mode is preferably achieved when the pressure force islower than the applied spring force. In one alternative of the valve260, the valve member 261 has a symmetric cross section including a stemconfigured to fit within the manifold channel 267, a first overhangextending from the stem, and a second overhang extending from the firstoverhang. The valve body 262 includes a cross section complimentary tothe valve member cross section, including a first step defining themanifold channel 267, a second step extending from the first step, andwalls extending from the second step. The first volume 264 is preferablydefined between the second step and the second overhang, the secondvolume 265 is preferably defined between the first step and the firstoverhang, and the connection channel is preferably defined between atransition from the first overhang to the second overhang and atransition between the first step to the second step. The valve 260 canfurther include gaskets bordering and cooperatively defining the firstand second volume 265 s. In one alternative of the valve 260, the valve260 includes a first gasket located within the connection channel thatforms a first substantially fluid impermeable seal with the valve member261 in the closed mode and a second fluid impermeable seal definedbetween the second overhang and the walls. The valve 260 canadditionally include a gasket within the manifold channel 267 that formsa fluid impermeable seal with the stem when the valve 260 is in theclosed mode (e.g., to cooperatively define the second volume 265), andpermits fluid flow therethrough when the valve 260 is in the open mode.

In one embodiment of the pump system 100, as shown in FIGS. 3A and 3B,the pump system 100 includes a first and a second reciprocating pump, adrive mechanism 300, a first and a second force translator 400 connectedto the first and second reciprocating pumps, respectfully, the first andsecond force translators having a first and second axis in fixedrelation, respectively, a fluid manifold fluidly connecting the secondreciprocating pump to a reservoir 20, and a valve 260 located within thefluid manifold. The first pump preferably includes an outlet fluidlyconnected to the reservoir 20, wherein the first pump pumps fluid to andpressurizes the reservoir 20 (as shown in FIG. 9A). The first pumppreferably includes an inlet fluidly connected to a fluid source,wherein the fluid source can be the ambient environment, the housing(e.g., wherein the housing encloses desiccated air), or any othersuitable fluid source. The second pump can additionally include an inlet(separate from that coupled to the fluid manifold but alternatively thesame one) and an outlet fluidly connected to the fluid source andreservoir 20, respectively wherein the second pump can pump fluid to andpressurize the reservoir 20. Alternatively, the inlet and outlet of thesecond pump can be fluidly connected to the fluid source and to theinlet of the first pump, respectively, thereby forming a two-stage pump.In this alternative, fluid is pressurized to a first pressure within thesecond pump and pressurized to a second pressure at the first pump. Thefirst and second reciprocating pumps preferably include a first andsecond pump chamber, respectively, and a first and second reciprocatingelement, respectively. The first and second reciprocating pumpspreferably share a common plane (e.g., the respective actuating axesshare a common plane), but can alternatively be located in differentplanes. The first and second reciprocating pumps are preferably equallyradially distributed about the drive mechanism 300, more preferablyequally distributed about the rotational axis of the drive mechanism300. However, the pumps can be otherwise distributed. The positions ofthe first and second pump chambers are preferably statically fixed by ahousing or other component, wherein the housing statically couples thepump system 100 to a rotating surface and can additionally enclose thepump system 100. The first and second reciprocating pumps preferablyoppose each other, wherein the closed end of the first pump chamber isdistal the closed end of the second pump chamber and the firstreciprocating element is proximal the second reciprocating element. Thefirst reciprocating element preferably has a first pressurization area(area that receives or generates a pressure force) and the secondreciprocating element preferably has a second pressurization area. Thefirst pressurization area is preferably smaller than the secondpressurization area, but can alternatively be larger or smaller. Thedrive mechanism 300 preferably includes a rotational axis, a cam 320rotatable about the rotational axis, the cam 320 having a bearingsurface, and an eccentric mass 340 coupled to the cam 320 that offsetsthe center of mass of the drive mechanism 300 from the rotational axis.The first force translator 400 is preferably couplable to the bearingsurface of the cam 320 in non-slip contact, and is preferably staticallyconnected to the reciprocating element of the first pump along an axis(e.g., rotational axis). The second force translator 400 preferablyslips relative to the bearing surface of the cam 320, but canalternatively couple in non-slip contact with the bearing surface. Thesecond force translator 400 is preferably statically connected to thereciprocating element of the second pump along an axis (e.g., rotationalaxis). The first and second force translators can each be a roller, apiston, a piston coupled to the roller at the rotational axis, or anyother suitable force translator 400. The positions of the first andsecond force translators are preferably statically retained by a frame242, but can alternatively be retained by any other suitable mechanism.The frame 242 preferably surrounds the drive mechanism 300, such thatthe drive mechanism 300 is located within the area bounded by the frame242. However, the frame 242 can be otherwise arranged relative to thedrive mechanism 300. The frame 242 is preferably located in the commonplane shared by the first and second pumps, but can alternatively belocated in a separate plane (e.g., extend normal to said plane andextend along a second plane parallel to the first). In operation, aradial or linear position of the frame 242 preferably shifts from afirst position to a second position relative to a point on the drivemechanism 300 (e.g., rotational axis) when the second reciprocatingelement moves from the depressurized position to the pressurizedposition, respectively. The distance between the first position and thesecond position is preferably substantially similar to the distancebetween the depressurized position and the pressurized position, but canalternatively be larger (e.g., wherein the frame 242 amplifies thechange in reciprocating element position) or smaller. Frame movementpreferably results in simultaneous first and second force translatormovement, coupling the first force translator 400 to the drive mechanism300 in the first position and decoupling the first force translator 400from the drive mechanism 300 in the frame's second position.Alternatively, frame movement can result in first and secondreciprocating pump movement relative to the drive mechanism 300, whereinthe frame 242 statically connects the positions of the first and secondpump chambers. However, the force translators can be otherwise connectedand disconnected to the drive mechanism 300. The frame 242 canadditionally include features, such as arcuate grooves on the surface ofthe frame proximal the drive mechanism, which facilitate second forcetranslator slip relative to the bearing surface. The fluid manifoldpreferably fluidly connects the reservoir 20 to an inlet of the secondpump, but can additionally fluidly connect the reservoir 20 to an inletof the first pump. In the latter alternative, the valve 260 ispreferably located upstream of the junction between the three fluidconnections or within the junction. In this latter alternative, valveopening simultaneously floods both lumens of the first and secondreciprocating pumps. Because second reciprocating pump preferably has alarger pressurization area than the first reciprocating pump, the secondreciprocating pump preferably exerts a linear (e.g., radial) decouplingforce on the frame 242 when pressurized, which is transferred by theframe 242 into a shift in the position of the first force translator 400away from the drive mechanism 300, effectively decoupling the firstforce translator 400 from the drive mechanism 300 (as shown in FIG. 9B).

As a person skilled in the art will recognize from the previous detaileddescription and from the figures and claims, modifications and changescan be made to the preferred embodiments of the invention withoutdeparting from the scope of this invention defined in the followingclaims.

I claim:
 1. An energy extraction system that extracts energy from arotating surface having a normal vector at a non-zero angle to a gravityvector, the system comprising: an extraction mechanism configured tostatically mount to the rotating surface; an eccentric mass operablebetween: a rotating mode, wherein the extraction mechanism rotatesrelative to the eccentric mass during rotating surface rotation andextracts energy from the relative rotation; and a non-rotating mode,wherein the extraction mechanism is static relative to the eccentricmass during rotating surface rotation and ceases energy extraction. 2.The system of claim 1, further comprising a force element thatselectively fixes an angular position of the eccentric mass in thenon-rotating mode to an angular position of the extraction mechanismrelative to the gravity vector.
 3. The system of claim 2, wherein theforce element comprises a friction element.
 4. The system of claim 1,wherein the extraction mechanism comprises a pump comprising anactuating element reciprocally coupled to a chamber, the pump operablein an extraction mode, wherein the actuating element is operable betweena first position and a second position in the extraction mode.
 5. Thesystem of claim 4, further comprising an drive component staticallyconnected to the eccentric mass and configured to move the actuatingelement between the first and second positions based on an angularposition of the extraction mechanism relative to the eccentric mass. 6.The system of claim 5, further comprising a force element thatstatically fixes the eccentric mass to the extraction mechanism in thenon-rotating mode.
 7. The system of claim 6, wherein the force elementapplies a radial force against the drive component in the non-rotatingmode sufficient to cease eccentric mass rotation relative to theextraction mechanism.
 8. The system of claim 7, wherein the forceelement is coupled to the drive component in the rotating mode, whereinthe force element is connected to the actuating element and translatesthe angular position of the extraction mechanism relative to theeccentric mass into a varying force applied to the actuating element inthe rotating mode.
 9. The system of claim 8, wherein the drive componentcomprises a cam with an arcuate bearing surface having non-uniformcurvature.
 10. The system of claim 9, wherein the force elementcomprises a roller having a rotation axis fixed to the actuatingelement, the roller configured to roll along the arcuate bearingsurface, wherein the pump is further operable in a pressurized modewherein the actuating element is operable in a third position furtherfrom a chamber end than the first and second positions, wherein theeccentric mass is placed in the non-rotating mode in response to pumpoperation in the pressurized mode.
 11. A tire inflation systemconfigured to mount to a wheel supporting the tire, the systemcomprising: a pump configured to statically mount to the wheel andconfigured to rotate about a revolution axis; a counterweight offsetfrom the revolution axis and rotatably coupled to the pump, thecounterweight operable between a rotating mode during wheel rotation,wherein the counterweight rotates relative to the pump, and anon-rotating mode during wheel rotation, wherein the counterweight isstatic relative to the pump; and a force element operable between acoupled mode wherein the force element statically couples counterweightrotation to pump rotation to place the counterweight in the non-rotatingmode and a decoupled mode wherein the force element decouples thecounterweight rotation from the pump rotation to place the counterweightin the rotating mode.
 12. The system of claim 11, wherein the forceelement is in the coupled mode when a tire pressure exceeds a firstthreshold.
 13. The system of claim 12, wherein the force element is inthe decoupled mode when the tire pressure falls below a secondthreshold, the system further comprising a valve fluidly connecting theforce element to a tire, the valve operable between an open mode inresponse to the tire pressure exceeding the first threshold and a closedmode in response to the tire pressure falling below the secondthreshold.
 14. The system of claim 11, wherein the force elementcomprises a friction element, wherein the force element staticallycouples the counterweight to the pump using friction.
 15. The system ofclaim 11, wherein the force element applies a coupling force along avector parallel to a normal vector to the revolution axis.
 16. Thesystem of claim 11, wherein the force element is fluidly connected to atire interior, wherein the coupling force is generated by a tirepressure.
 17. The system of claim 16, further comprising a valve fluidlyconnected between the force element and the tire interior, the valveoperable between an open mode in response to the tire pressure exceedingthe first threshold and a closed mode in response to the tire pressurefalling below the second threshold.
 18. The system of claim 11, furthercomprising an drive component connected to the counterweight andconfigured to actuate the pump between a compressed position and arecovered position based on an angular position change of the pumprelative to the counterweight.
 19. The system of claim 18, wherein theforce element applies the coupling force to the drive component.
 20. Thesystem of claim 19, wherein the force element is fixed to the actuatingelement, wherein the actuating element is further operable in apressurized state, wherein the force element is operated in the coupledmode in response to the actuating element operating in the pressurizedstate.
 21. The system of claim 20, wherein the drive component comprisesa cam with an angular bearing surface having a non-uniform curvature,the arcuate bearing surface coupled to a reciprocating element of thepump, wherein the actuation position of the pump is determined by thecurvature of the cam proximal the pump.
 22. A method of automatic tireinflation using a wheel-mounted tire inflator, the method comprising:while a tire pressure is below a threshold: retaining an angularposition of an drive component relative to a gravitational vector;pumping air into the tire using relative rotation between the drivecomponent and a pump; and in response to tire pressure exceeding thethreshold, statically coupling the angular position of the drivecomponent to an angular position of the pump.
 23. The method of claim22, wherein statically coupling an angular position of the drivecomponent to an angular position of the pump comprises staticallycoupling the drive component to the pump by applying a coupling force tothe drive component.
 24. The method of claim 23, wherein applying thecoupling force to the drive component comprises pressurizing the pump,wherein the pressurized pump applies the coupling force against thedrive component.
 25. The method of claim 23, wherein applying thecoupling force to the drive component comprises applying a frictionforce to the drive component, the friction force sufficient to overcomea force retaining the angular position of the drive component relativeto the gravitational vector.
 26. The method of claim 25, whereinapplying a friction force to the drive component comprises forcing aforce translator against the drive component, wherein the forcetranslator translates pump rotation relative to the drive component intopump reciprocation while the tire pressure is below the threshold.